Maternal care, including by non-biological parents, is important for offspring survival1–8. Oxytocin1,2,9–15, which is released by the hypothalamic paraventricular nucleus (PVN), is a critical maternal hormone. In mice, oxytocin enables neuroplasticity in the auditory cortex for maternal recognition of pup distress15. However, it is unclear how initial parental experience promotes hypothalamic signalling and cortical plasticity for reliable maternal care. Here we continuously monitored the behaviour of female virgin mice co-housed with an experienced mother and litter. This documentary approach was synchronized with neural recordings from the virgin PVN, including oxytocin neurons. These cells were activated as virgins were enlisted in maternal care by experienced mothers, who shepherded virgins into the nest and demonstrated pup retrieval. Virgins visually observed maternal retrieval, which activated PVN oxytocin neurons and promoted alloparenting. Thus rodents can acquire maternal behaviour by social transmission, providing a mechanism for adapting the brains of adult caregivers to infant needs via endogenous oxytocin.

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Background-Traumatic experiences may lead to debilitating psychiatric disorders including acute stress disorder and post-traumatic stress disorder. Current treatments for these conditions are largely ineffective; therefore, novel therapies are needed. A cardinal symptom of these pathologies is the re-experiencing of the trauma through intrusive memories and nightmares. Studies in animal models indicate that memories can be weakened by interfering with the post-retrieval re-stabilization process known as memory reconsolidation. We previously reported that, in rats, intra-amygdala injection of the glucocorticoid receptor antagonist RU38486 disrupts the reconsolidation of a traumatic memory. Here we tested parameters important for designing novel clinical protocols targeting the reconsolidation of a traumatic memory with RU38486.

Animals respond to changing contingencies to maximize reward. The orbitofrontal cortex (OFC) is important for flexible responding when established contingencies change, but the underlying cognitive mechanisms are debated. We tested rats with sham or OFC lesions in radial maze tasks that varied the frequency of contingency changes and measured both perseverative and non-perseverative errors. When contingencies were changed rarely, rats with sham lesions learned quickly and performed better than rats with OFC lesions. Rats with sham lesions made fewer non-perseverative errors, rarely entering non-rewarded arms, and more win-stay responses by returning to recently rewarded arms, compared to rats with OFC lesions. When contingencies were changed rapidly, however, rats with sham lesions learned slower, made more non-perseverative errors, fewer lose-shift responses, and returned more often to non-rewarded arms than rats with OFC lesions. The results support the view that the OFC integrates reward history, and suggests that the availability of outcome expectancy signals can either improve or impair adaptive responding depending on reward stability.

Memory can inform goal-directed behavior by linking current opportunities to past outcomes. The orbitofrontal cortex (OFC) may guide value-based responses by integrating the history of stimulus-reward associations into expected outcomes, representations of predicted hedonic value and quality. Alternatively, the OFC may rapidly compute flexible "online" reward predictions by associating stimuli with the latest outcome. OFC neurons develop predictive codes when rats learn to associate arbitrary stimuli with outcomes, but the extent to which predictive coding depends on most recent events and the integrated history of rewards is unclear. To investigate how reward history modulates OFC activity, we recorded OFC ensembles as rats performed spatial discriminations that differed only in the number of rewarded trials between goal reversals. The firing rate of single OFC neurons distinguished identical behaviors guided by different goals. When Ͼ20 rewarded trials separated goal switches, OFC ensembles developed stable and anticorrelated population vectors that predicted overall choice accuracy and the goal selected in single trials. When Ͻ10 rewarded trials separated goal switches, OFC population vectors decorrelated rapidly after each switch, but did not develop anticorrelated firing patterns or predict choice accuracy. The results show that, whereas OFC signals respond rapidly to contingency changes, they predict choices only when reward history is relatively stable, suggesting that consecutive rewarded episodes are needed for OFC computations that integrate reward history into expected outcomes.

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